Tumbler for safety locks



Patented May 15, 1928.

PATENT OFFICE. I

.FRITZ seHo'E'L'oE WETZTKON, SWITZERLAND, AssIGNoE To THE Finn: BAUER A.G.,

. .y or ZURICH, SWITZERLAND.

TUMBLEE Eon SAFETY Locxs.

Application filed June 21, 192e,- sermi No. 117,307, and in Germany July 29, 1925.

Vith the tumbler locks heretofore known, double-bit keys could render their full service only in such cases where the tumblers of a series had enough friction between themselves to prevent them from automatically changing their position. As soon as they became loose, a single bit would be sufficient for setting them, because when acting each would be carried alone and byits vown Weight into the right position for permitting free passage of the bolt. Sometimes tapping or knocking the lock would assist in bringing about this result. It will thus be seen that if a single bit is sufficient the imitation of the lock is lrendered much easier and consequently the protection afforded thereby is considerably reduced.

The object of the present invention is to rovide a tumbler which requires absolutely both of the bits of an opposed bit key for setting it, thereby greatly increasing the security of the lock. This result is accomplished by making the gating in the tumbler for the fence pin of the bolt normally too small for the passage of said pin, but capable of being enlarged to permit such passage only when both of the key bits are brought into action.

In the accompanying drawing the figure illustrates a face view of the tumbler.

Referring to the drawing, the tumbler is formed of a blank of resilient material provided with a bolt hole a in the well-known generally accepted manner, said hole serving to receive the swing bolt. The blank is also provided with an opening /1 -tor the reception of a double bit key, a gating c for the fence pin cl of a bolt According to the present invention the width of the gating c in the inoperative or normal position of the tumbler is slightly less than the width f of the fence pin d, so that the latter cannot pass through the gating even though the tumbler may be set in the right position to bring the gating into alinement with the fence pin. The blank is divided longitudinally by slits g and L into two equal parts t and t which are united at one end of the blank by a narrow portion t'. This permits an elastic spreading of the two parts under the action of the key bits sl'and S2 for enlarging the gating c to permit free passage of the fence pin. vIt is obvious that in order to accomplish this both bits of the key are necessary, because by' the use of a key with a single bit, for

instance Ithe bit 81 alone, all thatv would be accomplished would bea rotation of the tumbler While the width of the gating c would remain unaltered,

For the purpose of preventing undue enlargement of the gating c by the use of too large a key, which might permanently en-` limiting the spreading of the gating to a certain extent. The same result can be accomplished by making only a few of the tumblers of a series in the manner described, the others being provided with the ordinary well-known gating corresponding with the width of the fence pin f. VIn this manner any undesirable spreading of the two parts of the tumblers is avoided.

It will, of course, be readily understood that, instead of making the two partsof the tumbler integral, they may be entirely separate members resiliently connected together in any suitable manner.

It will be seen from the foregoing that the key must be of exactly a certain shape and size, since if it is the slightest bit too small it will not open the gating suiiiciently to permit passage of the fence pin. On the other hand, if the key is too large the head Z of the bridge m will prevent turning of the key. Both bits of the key must therefore be absolutely fitted tothe lock, so that imitation is rendered extremely difficult.

Having now particularly described they nature of my said invention what I claim as new, and desire to secure by Letters Patent, is zv 1. A lock tumbler, comprising a pair of resiliently united members adaptedto move toward and from each otherand forming between them a gating for the passage of a fence pin, said gating being normally narrower than the width of the fence pin, said movable members having between themv an opening for the reception of a double-bit key, said opening lbeing of such form that ke said o eninv beine-y o such formithat- 5 Vb t1 the turning of the key Will move the members apart to permit passage of the yfence pin.

2. A 'lock "tumbler, comprising a pair of resiliently united :members adapted'to move towardi andvfrom'V eac'hdother andiformingl vbetween them a gating for the passage olii? a fence pin, said gating being normally narrower than the width of the renee pin, said: movable members having between, them 2.111v

opening lfor the reeep'tion of a doublebi't toward Aand' from ear'h other andr formingl between thema gating for the passage ofa fence pin, said gating being normal-ly narrower than the Width of the fence pin, said movable members havin-g between, theman opening for the reception of a double-bit i key, Said Opening being of suchl form that the turning of the key will move the members apart to permit passage of the fence pin, one of said movable members having anopeningandthe other-'a'bridge member provided' with a h ead seated in said opening,

theshape and relative sizes of said opening and' head' being such as to permit only a 11mited separating movement et sait-l members.

4. A lock tnmbler, comprising a blank vof resilient materia-l; termin-g, a pair @t mem# bers unitedat one end by a. narrow stript said members having formed betweenr thenaf a gating and an open-ing for theI reception, of a double-bit'keygL the contour-of the; Walls ofsaid opening bei-ng such that the.- turning`r oli'- the key will' spreadV the members apart thereby to Widen said atjing.-

In testimony whereofl I have siigfned name tothis. specicationa FRITZ. SQHOR'L.. 

